A Strong Message to Pharmacists about IgG Food Sensitivity Testing

The Canadian Society of Allergy and Clinical Immunology (CSACI) is very concerned about the increased marketing of food-specific immunoglobulin G (IgG) testing towards the general public over the past few years, supposedly as a simple means by which to identify “food sensitivity”, food intolerance or food allergies. In the past, this unvalidated form of testing was usually offered by alternative or complementary health providers, but has now become more widely available with direct-to-consumer marketing through a nationwide chain of pharmacies.

There is no body of research that supports the use of this test to diagnose adverse reactions to food or to predict future adverse reactions. The literature currently suggests that the presence of specific IgG to food is a marker of exposure and tolerance to food, as seen in those participating in oral immunotherapy studies. Hence, positive test results for food-specific IgG are to be expected in normal, healthy adults and children. Furthermore, the inappropriate use of this test only increases the likelihood of false diagnoses being made, resulting in unnecessary dietary restrictions and decreased quality of life. The immediate expense of the test to individuals (see below for details on cost) will be compounded by the costs incurred by an already-overburdened health care system. Confused by the information provided by IgG testing, individuals are likely to request additional specialist referrals and investigations which would otherwise not be necessary.

Additionally, and perhaps of greater potential concern, a person with a true immunoglobulin E (IgE)-mediated food allergy, who is at significant risk for life-threatening anaphylaxis, may very well not have elevated levels of specific IgG to their particular allergen, and may be inappropriately advised to reintroduce this potentially deadly item into their diet.

As a result of these serious and growing concerns, the CSACI has elected to issue a formal statement supporting the opinions expressed by the American Academy of Allergy Asthma and Immunology (AAAAI) [1], and by the European Academy of Allergy and Clinical Immunology (EAACI) [2]. Both of these organizations warn about the inappropriate measurement of food-specific IgG or IgG4 to suggest the presence or potential of adverse reactions to food. Recent guidelines emphasize that such testing plays no role in the diagnosis of food allergy or intolerance [3]. A recent Canadian publication also elaborates similar concerns from the perspective of community allergy practice [4].

In addition to content of all of the above documents, the CSACI is very concerned about the following issues:

1. The testing process is widely available in Canada, through a variety of complementary health providers, paramedical clinics, and some physicians.

2. A testing kit product is being sold directly to customers, in pharmacies.

3. Marketing strategies for the testing have included the placing of promotional materials in the waiting rooms of physicians without their knowledge or consent.

4. The price of the testing is often in the $400-$700 range, and some third-party payers offer reimbursement despite a clear lack of supporting evidence.

5. The test is also being marketed to concerned parents, and may lead to exclusion diets which carry risks of poor growth and malnutrition for their children: for example, the elimination of dairy products, wheat, eggs, and/or other foods found in healthy balanced diets.

In summary

The CSACI does not support the decision of licensed physicians and our pharmacist colleagues to offer such testing, given the overwhelming consensus against the validity of such tests.

The CSACI strongly discourages the practice of food-specific IgG testing for the purposes of identifying or predicting adverse reactions to food. We also wish to remind the medical community that blood testing of any kind cannot substitute for consultation with a trained and accredited medical professional such as an Allergist/Immunologist for the diagnosis and management of adverse reactions to food.

If your pharmacy sells these tests – take your business to another pharmacy.

Couldn’t agree more!! It is so misleading and causes people to unnecessarily restrict healthy foods they don’t need to. It is also hard as a regulated health professional to debunk these tests with our clients when pharmacies are the ones giving them out (making it legitimate in their eyes).

Methinks the “credible” allergy organizations protest too much. Who exactly gains from their “debunking” this “myth”? The people? I think not. It reminds me of the huge fuss made over chiropractic treatments a few years ago. Only to find that: yes, chiropractic works if done by reputable practioners; and no, the complaining doctors aren’t actually losing any business!

Agree! I found this test to be right on target with my food allergy issues… and Chiropractic works! Western Medicine needs to incorporate more Eastern Medicine methods of healing… we would not need insurance except for emergencies. In my opinion.

Carolyn – who gains from their “debunking”? The patients do. Many parents of young children are undertaking this type of testing believeing it to be the same testing that allergists do, so they truly believe their child is allergic to all those foods. Bottom line is if this testing offered any benefits in the diagnosis of allergies, then allergists would be using them. It’s time that message got out there.

I’m not suggesting that this information shouldn’t be available. It’s good to have discussions and studies on the effectiveness of anything purporting to be “healthy”. I’m asking that before jumping on the bandwagon to debunk this test as useless, that people think about where the claim is coming from. Do you know who is doing the debunking? The companies making allergy medication. Sounds like they have vested interest. As for allergists not using these tests, some are using them in addition to the standard tests.

We need more time and research to accurately determine if this is useful info or not.

IgG test results are not specific or sensitive for reactions. See the citations linked to. Whether or not there is a correlation is akin to rolling dice. That’s why legitimate allergy specialists don’t use IgG testing – it isn’t reliable.

“Do you know who is doing the debunking? The companies making allergy medication.”

“We need more time and research to accurately determine if this is useful info or not.”

The tests have been done and the testing isn’t reliable. See the papers linked to in the articles. IgG testing is clinically useless. That’s why only alternative medicine practitioners offer it. If it worked, it wouldn’t be “alternative”. It would be a standard part of medical practice. If it did work, vendors of these tests would provide evidence that the testing worked. No credible evidence has been published.

All “standard” practices were once alternatives. Should we still be bleeding people? It used to be a common treatment. Just because something is widespread doesn’t mean that it works for everyone. Just because these tests are “alternative” doesn’t mean that they don’t work. My family and myself have found IgG test to be useful in conjunction with more standard types of testing.

Just what company, and what medication? I work with kids with legitimate food allergies every day, and they are not taking any chronic medication. They carry Epipens. If IgG testing worked, and increased the number of people with food allergies, then you would think the Epipen people would be all over it! In fact, wouldn’t they be trying to market it themselves? Increase their market for their once-a-year medication? Your argument makes no sense whatsoever. The allergists appear to be doing the debunking, and what’s in it for them? They would probably only get more patients this way since this testing provides so many false positives. I have also been trying to debunk this type of testing for a while, and my only interest is in protecting the children I see who have unnecessary food restrictions placed on them. I have even been asked to personally “sell” IgG testing, complete with glossy tables and graphs showing me how much money I could make. No thanks.

I’m not talking about severe allergies that require an epipen. I think my use of the word allergy was misleading. I should have said food sensitivities or intolerances. Which rarely require medication, therefore no profit to drug manufacturers.

Isn’t it amazing that people who do not have the faintest idea about what IgG antibodies are or how allergies manifest feel that they have more expertise than physicians or pharmacists or researchers who have spent years studying antigen-antibody reactions?

In our pharmacy we do offer the IgG testing if a person is already working through GI difficulties or migraines or eczema, etc. I have personally counseled hundreds of people, however, to first try some elimination diets (note: otherwise healthy adults) to try eliminating foods such as dairy or wheat. Always just one food at a time and if it is igG related, a person can eliminate it for one week and on the eighth day consume that food in dominance and still have the antibodies circulating thereby trigger a ‘flare’ of the symptoms. The testing ranges from $150-250 and is virtually painless, opens up positive discussion between the clinical pharmacist, patient and their physician, and shad the potential to really help people navigate the effects of what they ate putting in their bodies. IgG-mediated reactions are not clinically the same as IgE reactions and many of us never learn about conditions related to overreactivity here but it is something we should pay attention to as clinicians wherever it may truly benefit the patient. These patients may already be looking at spending $12-1500 per consultation with an alternative practitioner and not relatively find paying out of pocket for tests a problem whatsoever. I think we will only see more of this actually. Who do I feel could be threatened in this? Likely agriculture that produces dairy and wheat. These two food items alone, when eliminated, do not result in ill health but if a nation turned away from them en masse, it could disrupt major industry profits.

You’re selling IgG testing despite the overwhelming evidence showing that it is unvalidated and ineffective. In addition to the multiple references I have mentioned (linking to position statements from allergy and immunology experts), note this, from the EAACI Task Force Report, Testing for IgG4 against foods is not recommended as a diagnostic tool:

An important conclusion from these investigations was that the IgG tests were only useful to provide information in epidemiological studies, meaning that they gave no relevant information on an individual basis: it is obvious that treatment, such as dietary intervention based on the presence of food-specific IgG(4) for these test groups, would have resulted in massive overtreatment. Another observation from both the investigations was that there were no indications that food-specific IgG(4), which appeared to be common in the young population, was associated with food-allergic complaints, even at the population level.

and

Food-specific IgG4 does not indicate (imminent) food allergy or intolerance, but rather a physiological response of the immune system after exposition to food components. Therefore, testing of IgG4 to foods is considered as irrelevant for the laboratory work-up of food allergy or intolerance and should not be performed in case of food-related complaints (21).

This article may be old and superceded by events but I am posting this to clear up misconceptions that steered us away from this kind of testing and only years later we discovered that it was in fact useful.

Want Evidence?

Mayo Clinic, the New York Times, and the medical journal Cephalagia all seem to support IGG allergy testing due to recent peer reviewed published science, see:

Also my wife, who has had migraines for years is helped by avoiding these foods.

So, although I’ll admit this is all experimental, alternative, and inconclusive, there seems to be significant legitimate benefits to IGG allergy testing.

I personally have IGE allergies, and have been helped by sublingual immunotherapy, which is also experimental and unproven. However, there is no better treatment available, and in europe this is an accepted treatment now.

So while the medical establishment is catching up and discovering things in all these areas constantly, people are seriously not feeling well now.

Sure it’s a gamble, but there is a lot in medicine that is unknown, and there is no need to be down on a treatment just because it’s not proven.

People here keep saying there is “overwhelming evidence showing that it is unvalidated and ineffective”. That’s not accurate at all. Where is that evidence.

There is not a lot of evidence that it works, but that is completely different from saying there is evidence to suggest it doesn’t.